KAM resin snaps have an OekoTex cetification of "no harmful substances" - I have a PDF on that one if you need it.
Snap Source has tested their snaps - see this site:
http://www.snapsource.com/whatsnew/whatsnew.phpPrym (also known as Dritz) has a site where you can type in the product number or UPC code to see if the package of snaps you have is compliant or not:
http://gcc.dritz.com/Maybe that will help. Of course, you could be right about those snaps you originally looked for. I haven't checked my ones from Tandy Leather, but I have a feeling they're "not for children" either.